Lettuce knife



FIG. 1 is a side perspective view of a lettuce knife showing an exemplary embodiment of our new design;

FIG. 2 is a left side view of the lettuce knife of FIG. 1;

FIG. 3 is a right side view of the lettuce knife of FIG. 1;

FIG. 4 is a back view of the lettuce knife of FIG. 1;

FIG. 5 is a front view of the lettuce knife of FIG. 1;

FIG. 6 is a top view of the lettuce knife of FIG. 1; and,

FIG. 7 is a bottom view of the lettuce knife of FIG. 1. 

The ornamental design for a lettuce knife, as shown. 